This invention is related to orthopedic equipment and concerns, more particularly, equipment intended to permit the reduction and knitting of bone fractures by holding and realignment, especially those of the lower and upper limbs.
The invention essentially concerns external orthopedic holding appliances as compared to internal holding appliances made up, for example, of screwed plates, pins, etc.
If orthopedic reducing devices fastening internally do certainly make it possible to achieve the result of reduction and knitting of a fracture, it is clear that the use of them involves an invasive method, seeing that the practitioner is forced to open up the traumatized limb to reach and free the fractured bone in order to be able to fit a plate, strip or pin attached by screws implanted in bony material to the segments of that bone. So it is a matter of a surgical operation which may be awkward, with the consequences which may attend such practices even if these are generally well mastered.
The object of external orthopedic holding devices is to eliminate such a surgical operation by implanting directly a kind of external lateral harness, by means of pins passing through the flesh and fixed in the bone segments, insuring the immobilization of the fractured bone segments in the position required.
Prior art is familiar with various proposals to this effect. By way of indication one may mention the ILIZAROF external fastening device, the main drawback of which is the need to use a large number of through pins which are implanted in different directions in the bone, passing through the flesh. The use of such a fastening device is extremely delicate, since, in order to implant the various pins, it is absolutely necessary to insure that they pass between the muscles without traumatizing the nerves, tendons or arterial and venous systems.
Also known in prior art is an external fastening system known as that of HOFFMANN, using, between the through pins for fastening, connecting and supporting devices which are relatively clumsy and difficult to adjust.
There was a development in simplicity of design with the OSTEO external holding appliance, composed of two telescopic parts adjustable relative to each other, the ends of which are equipped with devices for locking and orienting through pins. If such a device unquestionably represents a simplification of previous appliances, consideration must be given to the fact that the proposal formulated leads to a clumsy appliance with little possibility of simple, quick and easy adjustment of the direction of the fin-locking devices to correspond to the preferred direction of implantation of those pins.
It is also appropriate to mention another suggestion known by the name of dynamic axial attachment system proposed by the ORTHOFIX Company. Such an appliance is composed of an elongated support of adjustable length, the ends of which are equipped with position-adjusting devices for two end flanges connected to through pins. The position-adjusting devices at each end are composed of a locking pin which proves in practice to allow a certain amount of slippage, irremediably and detrimentally modifying the relative alignment between the fractured segments of a bone to be reduced and knit together.
The purpose of the invention is to respond to the problem posed by the external attachment (of fractured bone segments by proposing a new brace of light, but sturdy design which can be adjusted in a rapid, sure and durable manner, as regards both length and position adjustment, so as to offer every possibility of adaptation to preferred directions or through pins which have to be immobilized relatively to insure the proper and correct alignment of fractured segments, then, maintenance in a reduced state and their knitting together over time.
Another purpose of the invention is, by simple adaptation, to permit a relative, limited, elastic cushioning function, when, for example, there is a need to have the brace perform a possible function of alternate compression of the line of fracture so as to reinforce over time the knitting together being established.
Another purpose of the invention is also to make it possible to have the external brace assume, if need be, a function of elongation when such a method has to be applied, which is itself familiar in any case.
Another purpose of the invention is to propose a new brace with relatively little bulk so as to allow external fitting close to the traumatized limb.
A further purpose of the invention is to offer a brace allowing X-ray photographs to be taken without dismantling, without its components being obstacles concealing the bony parts to be X-rayed.
In order to attain the above objectives, the external brace according to the invention is characterized by the fact that
the telescopic parts are of an X-ray transparent material and form two transverse plates at their opposite ends; PA1 the locking mechanism consists of a slide working in conjunction with two collet chucks fitting the periphery of the plates; PA1 in the case of each flange, the position-adjusting devices are made up of three threaded rods at equidistant angles, individually adjustable in length and mounted in the corresponding plate with three ball-and-socket joints to extend, in the neutral position, parallel to tie axis of the telescopic elements.